The present invention is directed to a retainer for non-rotatably retaining a conduit that extends through a casing or wall. More particularly, the present invention relates to a conduit retainer for use in a high temperature environment, such as adjacent a combustor of a gas turbine engine, that retains a conduit against rotation.
In gas turbine engines, several tubular conduits are provided that extend through an outer annular casing that surrounds the engine. Such conduits are provided for conveying fluids such as pressurized air, for cooling engine components subjected to very high temperatures, and oil, for lubricating bearings supporting rotating components of the engine. Because of vibrations that are encountered during engine operation, it is desirable to restrain such conduits from rotational motion about their own axes to retain them in the desired positions. Additionally, there is a possibility of leakage of high pressure air or gas from within the engine at the conduit-casing junction. Such leakage gas can impinge upon the adjacent structure that surrounds the engine, such as airframe and engine nacelle structural elements. And because some of the conduits extend through the engine casing at points where the air or gas within the interior of the casing is at a relatively high temperature, such as the combustor portion of the casing or the compressor discharge portion of the casing, where internal temperatures can be of the order of about 1,000xc2x0 F. or so, it is desirable to deflect such leakage flow laterally, away from the structure that surrounds the engine casing.
One form of retainer that has been utilized in the past is an annular disk having serrations around its inner periphery and including a pair of outwardly extending tabs to secure the retainer to the engine casing. The serrations engage the periphery of the conduit to prevent rotation of the conduit about its own axis. However, because of the varying forces that are imposed on such conduits during engine operation and during aircraft maneuvers, including vibratory forces, the stresses to which the conduit retainers are subjected include cyclic stresses induced by vibrations, and they sometimes result in fatigue-induced cracking of the annular disk portion of the retainer.
It is therefore desirable to provide a conduit retainer that non-rotatably supports the conduit, that serves to diffuse or deflect the leakage air that exits at the conduit-casing junction, and also to withstand the cyclic stresses that are encountered during engine operation.
Briefly stated, in accordance with one aspect of the present invention, a retainer is provided for retaining a conduit member that extends through a wall. The retainer includes an annular top wall having an outer edge and having an opening that includes a plurality of contact surfaces for cooperative engagement with a conduit member to be retained. A depending skirt extends from the outer edge at one face of the top wall for a predetermined length and terminates at a free end. At least two circumferentially-spaced legs extend from the free end of the depending skirt, and each leg carries a radially-outwardly-extending tab. Each tab includes a bolt opening for receiving a connecting bolt for attaching the retainer to the wall through which the conduit member extends.